Door latch



June 5, 1956 J HARR|5 2,749,158

DOOR LATCH Filed July 26, 1955 Fig. //2

Asa J Harris INVENTOR.

United States Patent V DOOR LATCH Asa J. Harris, Harbor Island, N. C.

Application July 26, 1955, Serial No. 524,420

1 Claim. (Cl. 292-230) This invention generally relates to a door latch,and more specifically provides an improved and novel structure over thatof my previous Patent No. 2,452,461, issued October 26, 1948.

An object of the present invention is to provide means for automaticallylatching a hinged door in an open position and to permit release thereofby turning of the door knob in either rotational direction.

Another object of the present invention is to provide a door latch thatis equipped with a resilient cushion or bumper to prevent rattling andto act as a buffer or bumper for the door knob.

A further important object of the present invention is to provide a doorlatch which is simple in construction, easy to manipulate, substantiallyautomatic in latching operation, constructed of a minimum of exposed andmoving parts, well adapted for its intended purposes and relativelyinexpensive to manufacture.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

Figure 1 is a side elevational view of the door latch of the presentinvention with portions thereof being broken away illustrating theinternal construction of the hollow door knob together with theprojecting member with the latch member pivoted thereto;

Figure 2 is a sectional view similar to Figure 1 illustrating theposition of the door knob when the door knob has been moved to anunlatched position;

Figure 3 is a transverse sectional view taken substantially upon a planepassing along section line 33 of Figure 1 illustrating the relationshipof the pivotal latch member and the door knob when in latched position;

Figure 4 is a sectional View taken substantially upon the same plane asFigure 3 showing the position of the door knob when it is in unlatchedposition; and

Figure 5 is an end view of the latch member and the buffer plate.

Referring now specifically to the drawings, the numeral generallydesignates the door latch of the present invention for attachment to apivotal door 12 for retaining the door 12 in position alongside asupporting structure such as a wall 14. The door 12 is provided with theusual catch 16 and operating bolt 18 therefor having the usual door knob20 on one end thereof. On the other end of the lock bolt 18 is a hollowdoor knob 22 which is secured thereon by the usual setscrew 24.

The hollow door knob 22 includes an enlarged hollow portion 26 with arelatively small cylindrical opening 28 in the center of the outer facethereof and a transversely extending flat bottom 38 in the hollowportion 26 spaced slightly below the lower edge of the opening 28 andjoined thereto by a generally concave portion 32.

Secured to the wall 14 is a base member 34 having an outwardly extendingprojecting member 36 integrally 2,749,168 Patented June 5, 1956 2 formedtherewith and a circular bumper or buffer plate 38 made of suitableresilient material for forming a cushion in surrounding relation to the"projecting member 36 and resting against the front surface of the baseplate 34 which may be attached to the wall 14 by any suitable means.

The outer end of the projecting member 36 isprovided with a pair ofspaced lugs 40'defining' aslot 42 for pivotally receiving a latch member44 which is pivot'ally mounted by a transverse pivotpin 46; The latchmem* ber '44 is of a width whichis substantially equal to the diameterof the cylindrical projecting member 36 and is rovided with a roundedouter end- 48' and a rounded inner end 50 wherein the inner end 50 isformed of a radius which is not more than the radius of the cylindricalmember 36 wherein the inner end 50 will at all times be disposed withinthe confines of the projecting member 36.

The latch member 44 is freely pivotal on the pivot pin 46 and isactuated by gravity to a normally dependent relation, substantially asillustrated in Figure 2.

The opening 28 in the door knob 22 is slightly larger than the peripheryof the projecting member 36 for permitting passage of the member 36 intothe hollow portion 26. When the projecting member 36 passes through theopening 28, the edges of the opening 28 engage the forward edge of thelatch member 44, thereby pivoting it rearwardly into the slot 42 betweenthe lugs 40 wherein the latch member 44 will be completely disposedwithin the confines of the projecting member 36. After the inner curvedend 48 of the latch member 44 passes the inner edge of the opening 28,the latch member 44 is moved downwardly by gravity to an inclinedposition, substantially as illustrated in Figure 1, wherein the freecurved end 48 is disposed against the concave junction 32 between thebottom 30 of the hollow portion 26 and the lower edge of the opening 28with the pivot pin 46 disposed inwardly thereof, thereby preventingwithdrawal of the projecting member 36 from the knob 22 for locking thedoor 12 in open position.

In order to release the latch member 44, it is only necessary to rotatethe knob 22 in either direction by gripping the knob 20, wherein thebottom 30 will move out of engagement with the free end 48 of the latchmember 44, substantially as illustrated in Figure 4, thereby permittingthe inner edges of the opening 28 to move the latch member 44 to aposition coextensive with and extending from the projecting member 36wherein the projecting member 36 may then be released from the door knob22 to permit movement of the door to a closed position.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

A door latch for retaining a door in an open position adjacent asupporting structure comprising a hollow door knob adapted to be mountedon the door for turning in opposite directions, said knob having anopening in the outer face thereof, a transverse horizontal bottom insaid hollow knob spaced below the lower edge of said opening, aprojecting member mounted on the supporting structure and adapted to beclosely received through said opening in the knob, and a pivotal latchmember mounted on said projecting member, said latch member beingnormally retained in depending relation by gravity, the free end of thelatch member being moved rearwardly to a position within the confines ofthe projecting member by the edge of the opening when the projectingmember passes through the opening, the free end of said latch memberthen falling downwardly and engaging the juncture between the horizontalbottom of the knob and the lower edge of said opening in an inclinedposition with the free end of the latch member disposed adjacent theopening and the free end of the projecting member being remote from theopening thereby preventing withdrawal of the projecting member from theopening, said hollow knob being sufficiently large whereby said latchmember may be disengaged from the bottom of the knob when the knob isturned in either direction for permitting the latch member to fallfreely to 21 depending position whereby the edges of the opening willmove the free end of the latch member forwardly to a positioncoextensive with the projecting memher when the projecting member iswithdrawn through the opening, said opening and projecting member beingcylindrical with the projecting member having a slot in the outer endfor pivotally receiving said latch member, said latch member havingrounded ends with the inner end being constantly within the confines ofthe projecting member.

References Cited in the file of this patent UNITED STATES PATENTS624,080 Pease May 2, 1899 1,728,693 Moore Sept. 17, 1929 1,834,163Lasier Dec. 1, 1931 2,452,461 Harris Oct. 26, 1948 2,544,611 KnottinghamMar. 6, 1951

